Prevalence of less severe hypercortisolism in fractured patients admitted in an outpatient clinic for metabolic bone diseases.

PURPOSE: To evaluate the prevalence of less severe hypercortisolism (LSH) in fractured patients, and its association with hypertension, hyperglicemia, dyslipidemia, and obesity. METHOD: From July 2015 to October 2018 we enrolled all fractured patients admitted in our outpatient center for metabolic bone diseases, after exclusion of patients with secondary osteoporosis apart from diabetes and taking drugs known to affect bone metabolism. In all enrolled patients we collected data regarding gonadal status, history of diabetes, high blood pressure, dyslipidemia, and measured blood pressure, lipid profile, fasting glycaemia. Bone mass was measured with DXA at lumbar spine and femoral neck and the presence of fractures was evaluated with X-ray of thoracic and lumbar spine. All patients performed twice, 1 mg overnight dexametasone suppression test (DST) and, as confirmatory, 2day low-dose DST for diagnosing hypercortisolism. RESULTS: We enrolled 101 fractured patients (75 females, 26 males), aged 65 ± 10.3 years. Five out of 101 (5.0%) patients were diagnosed as LSH. Fifty-five (54.5%) out of 101 were hypertensive, 57 (56.4%) dyslipidemic, 17 (16.8%) hyperglicaemic, 28(27.7%) obese patients. LSH tended to be associated to blood hypertension [5/5 vs 50/96 (Fisher exact test, p = 0.06) hypertensive patients]. Four out five LSH patients were hypogonadic. CONCLUSIONS: Our study confirms that a nonnegligible percentage of fractured subjects actually presents an unrecognized hypercortisolism. Accordingly, regardless of age, we suggest to screen for hypercortisolism all patients with established osteoporosis and in particular hypertensive subjects.

High serum osteopontin levels are associated with prevalent fractures and worse lipid profile in post-menopausal women with type 2 diabetes.

PURPOSE: Patients with type 2 diabetes (T2DM) have increased fracture risk. Osteopontin (OPN) is a protein involved in bone remodeling and inflammation. The aim of this study was to evaluate the association of OPN with fracture prevalence and with metabolic parameters in post-menopausal women with T2DM. METHODS: Sixty-four post-menopausal women with T2DM (age 67.0 ± 7.8 years, diabetes duration 8.9 ± 6.7 years), enrolled in a previous study, were followed up (3.6 ± 0.9 years). Previous fragility fractures were recorded. The FRAX score (without BMD) was calculated and biochemical parameters (plasma glucose, HbA1c, lipid profile and renal function) were assessed. Serum 25OH-vitamin D, calcium, PTH and OPN were evaluated at baseline. The association between OPN and fracture prevalence at baseline was evaluated by a logistic model. RESULTS: OPN levels were higher in patients with previous fractures (n.25) than in patients without previous fractures at baseline (n.39) (p = 0.006). The odds of having fractures at baseline increased by 6.7 (1.9-31.4, 95% CI, p = 0.007) for each increase of 1 ng/ml in OPN levels, after adjustment for vitamin D and HbA1c levels. Fracture incidence was 4.7%. Higher OPN associated with a decrease in HDL-cholesterol (p = 0.048), after adjustment for age, basal HDL-cholesterol, basal and follow-up HbA1c and follow-up duration. 25OH-vitamin D associated with an increase in FRAX-estimated probability of hip fracture at follow-up (p = 0.029), after adjustment for age, 25OH-vitamin D and time. CONCLUSIONS: In post-menopausal women with T2DM, OPN might be a useful marker of fracture and worse lipid profile.

Bone involvement and mineral metabolism in Williams' syndrome.

CONTEXT: The previous studies suggested a possible increased risk of hypercalcaemia and reduced bone mineral density (BMD) in Williams' syndrome (WS). However, an extensive study regarding bone metabolism has never been performed. OBJECTIVE: To investigate bone health in young adults with WS. DESIGN: Cross-sectional study. SETTINGS: Endocrinology and Metabolic Diseases and Medical Genetic Units. PATIENTS: 29 WS young adults and 29 age- and sex-matched controls. MAIN OUTCOME MEASURES: In all subjects, calcium, phosphorus, bone alkaline phosphatase (bALP), parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHVitD), osteocalcin (OC), carboxyterminal cross-linking telopeptide of type I collagen (CTX), 24-h urinary calcium and phosphorus, femoral-neck (FN) and lumbar-spine (LS) BMD and vertebral fractures (VFx) were assessed. In 19 patients, serum fibroblast growth factor-23 (FGF23) levels were measured. RESULTS: WS patients showed lower phosphorus (3.1 ± 0.7 vs 3.8 ± 0.5 mg/dL, p = 0.0001) and TmP/GFR (0.81 ± 0.32 vs 1.06 ± 0.25 mmol/L, p = 0.001), and an increased prevalence (p = 0.005) of hypophosphoremia (34.5 vs 3.4%) and reduced TmP/GFR (37.9 vs 3.4%). Moreover, bALP (26.3 ± 8.5 vs 35.0 ± 8.0 U/L), PTH (24.5 ± 12.6 vs 33.7 ± 10.8 pg/mL), OC (19.4 ± 5.3 vs 24.5 ± 8.7 ng/mL), and FN-BMD (- 0.51 ± 0.32 vs 0.36 ± 0.32) were significantly lower (p < 0.05), while CTX significantly higher (401.2 ± 169.3 vs 322.3 ± 122.4 pg/mL, p < 0.05). Serum and urinary calcium and 25OHVitD levels, LS-BMD and VFx prevalence were comparable. No cases of hypercalcemia and suppressed FGF23 were documented. Patients with low vs normal phosphorus and low vs normal TmP/GFR showed comparable FGF23 levels. FGF23 did not correlate with phosphorus and TmP/GFR values. CONCLUSIONS: Adult WS patients have reduced TmP/GFR, inappropriately normal FGF23 levels and an uncoupled bone turnover with low femoral BMD.

Voltage-Gated Sodium Channels: Evolutionary History and Distinctive Sequence Features.

Voltage-gated sodium channels (Nav) are responsible for the rising phase of the action potential. Their role in electrical signal transmission is so relevant that their emergence is believed to be one of the crucial factors enabling development of nervous system. The presence of voltage-gated sodium-selective channels in bacteria (BacNav) has raised questions concerning the evolutionary history of the ones in animals. Here we review some of the milestones in the field of Nav phylogenetic analysis and discuss some of the most important sequence features that distinguish these channels from voltage-gated potassium channels and transient receptor potential channels.

Bone damage in type 2 diabetes mellitus.

This review focuses on the mechanisms determining bone fragility in patients with type 2 diabetes mellitus (T2DM). Despite bone mineral density (BMD) is usually normal or more often increased in these patients, fracture incidence is high, probably because of altered bone "quality". The latter seems to depend on several, only partly elucidated, mechanisms, such as the increased skeletal content of advanced glycation end-products causing collagen deterioration, the altered differentiation of bone osteogenic cells, the altered bone turnover and micro-architecture. Disease duration, its severity and metabolic control, the type of therapy, the presence or absence of complications, as like as the other known predictors for falls, are all relevant contributing factors affecting fracture risk in T2DM. In these patients the estimate of fracture risk in the everyday clinical practice may be challenging, due to the lower predictive capacity of both BMD and risk factors-based algorithms (e.g. FRAX).

Effect of a single oral dose of 600,000 IU of cholecalciferol on muscle strength: a study in young women.

BACKGROUND: The effect of a single large oral dose of vitamin D on muscle function in young people with vitamin D deficiency has not been investigated so far. AIM: We evaluated the effect of a single oral dose of 600,000 IU of cholecalciferol on muscle strength. SUBJECTS AND METHODS: Eighteen young women with vitamin D deficiency received a single oral dose of 600,000 IU of cholecalciferol. We evaluated changes in maximal voluntary contraction (MVC) and speed of contraction (S) in response to cholecalciferol by using an hand held dynamometer at 3, 15, 30, 60 and 90 days, compared to baseline. RESULTS: We observed no significant change in MVC and S values, a significant increase of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D] and a significant decrease in serum parathyroid hormone (PTH) (p<0.001 for all). A significant correlation was found between MVC and S and serum phosphorus (P) after supplementation (p<0.02 and p<0.05, respectively). Conversely, we observed no association between the parameters of muscle strength and 25(OH)D, ionized calcium (Ca2+), PTH and 1,25(OH)2D. CONCLUSIONS: A single dose of 600,000 IU of cholecalciferol does not directly enhance handgrip strength in young women with vitamin D deficiency. More studies are needed on the indirect effect of the hormone on muscle.

Vitamin D and parameters of calcium homeostasis in inpatients with and without Type 2 diabetes mellitus.

AIM: We investigated inpatients with and without Type 2 diabetes mellitus, aged over 60 yr, to compare their vitamin D status and calcium homeostatic parameters. MATERIALS AND METHODS: We studied 140 patients consecutively admitted to our Internal Medicine Unit during the year 2010 (61 from November to April, 79 from May to October). The sample encompassed 70 patients with and 70 without diabetes. At admission we measured serum calcium (Ca), phosphate (P), sodium (Na), potassium (K), creatinine (Cr), alkaline phosphatase total activity (AP), albumin adjusted serum calcium (Caalb adj), 25 hydroxy-vitamin D (25OHD), PTH, and 24-h urinary Na/Cr (uNa/Cr), K/Cr (uK/Cr), Ca/Cr (uCa/Cr), P/Cr (uP/Cr) ratios, and calcium excretion (Ca ex). RESULTS: 25OHD levels of patients with and without diabetes did not significantly differ. In patients without diabetes recruited from November to April, 25OHD levels were significantly lower than those from May to October, whilst patients with diabetes did not show a significant seasonal variation. PTH had opposite non-significant seasonal variations, and negatively correlated with 25OHD in both groups of patients. This correlation was lost after adjusting for age and body mass index in patients with diabetes. These inpatients had higher serum P and lower uP/Cr, according to lower PTH. Their serum glucose negatively correlated with uCa/Cr and Ca ex, contrary to inpatients with other diseases. Instead, uCa/Cr and Ca ex correlated with uNa/Cr only in patients without diabetes. CONCLUSIONS: Inpatients with diabetes did differ from those with other disorders for vitamin D status and calcium-phosphate homeostatic mechanism.

Carboxyl-terminal parathyroid hormone fragments: biologic effects.

Carboxyl-terminal PTH fragments (C-PTH), are generated by both direct secretion from parathyroids in relation to serum calcium levels and catabolism of PTH operated by the Kupffer cells in the liver. These molecular fragments have been till recently regarded as inert byproducts of PTH metabolism, since they do not interact with the PTH/PTH-related peptide (rP) receptor, which mediates the classical hormone actions. Current findings instead indicate that C-PTH would interact with a putative C-PTH receptor. This way, C-PTH seem to exert specific effects on calcium homeostasis and bone metabolism, opposite to those of the synthetic agonist of PTH/PTHrP receptor (i.e. PTH 1-34). In vitro and in vivo data actually indicate that C-PTH, by interacting with specific receptors, could have an anti-calcemic action, as well as a pro-apoptotic effect on both osteocytes and osteoclasts. This in turn could result in a reduced activity of the latter cells, with a consequent inhibition of bone resorption.

Sporadic and hereditary primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is a common endocrine disorder, particularly frequent in post-menopausal women. It is characterized by hypercalcemia with inappropriately high spontaneous plasma PTH. Singlegland adenoma is the most common cause (75- 85%). PHPT is usually a sporadic disease but in approximately <5% of cases, a familial hyperparathyroid syndrome is diagnosed. Familial hyperparathyroidism is a clinically and genetically heterogeneous group of disorders including: multiple endocrine neoplasia (MEN) type 1, MEN type 2A, MEN4, benign familial hypocalciuric hypercalcemia, neonatal severe hyperparathyroidism, hyperparathyroidism-jaw tumor syndrome, and familial isolated hyperparathyroidism. These syndromes show mendelian inheritance patterns and the main genes for most of them have been defined. The classic form of PHPT, which presents with hypercalcemia, kidney stones, and bone disease, is no longer common. Currently, there is an increasing interest in the subtle manifestations of PHPT, particularly the cardiovascular and neuropsychiatric manifestations. Parathyroidectomy is the definitive cure for PHPT even though patients with the asymptomatic form of the disease can be followed conservatively.

[Guidelines on prevention and treatment of vitamin D deficiency. Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS)]. / Linee guida su prevenzione e trattamento dell'ipovitaminosi D con colecalciferolo. SIOMMMS.

The Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS) has elaborated the following guidelines about the definition, prevention and treatment of inadequate vitamin D status. The highlights are presented here. Daily vitamin D allowance ranges from 1,500 IU (healthy adults) to 2,300 IU (elderly with low calcium intake). Since the average Italian diet includes around 300 IU/day, subjects with no effective sun exposure should be supplemented with 1,200-2,000 IU vitamin D per day. The serum 25-hydroxy-vitamin D [25(OH)D] levels represents the most accurate way to assess vitamin D repletion, even though there are still no standardized assay methods. Conditions of "deficiency" and "insufficiency" are defined by the following ranges of 25(OH)D levels: less than 20 ng/ml and 20-30 ng/ml, respectively. In Italy, approximately 50% of young healthy subjects have vitamin D insufficiency during the winter months. The prevalence of deficiency increases with ageing, affecting almost all elderly subjects not on vitamin D supplements. When a condition of deficiency has been identified, a cumulative dose of 300,000-1,000,000 IU, over 1-4 weeks is recommended. In subjects recently treated for deficiency-insufficiency, a maintenance dose of 800-2,000 IU/day (or weekly equivalent) is recommended. In patients on daily doses over 1,000 IU, 25(OH)D levels should be checked regularly (e.g. once every two years). The highest tolerated daily dose has been identified as 4,000 IU/day. Vitamin D supplementation should be carefully monitored in patients at higher risk of vitamin D intoxication (granulomatosis) or with primary hyperparathyroidism. In pregnant women, vitamin D supplements should be given as in non-pregnant women, but bolus administration (i.e.: single dose >25,000 IU) should be avoided.

Relationship between bone metabolism and adipogenesis.

Several findings indicate that adipose tissue and bone have a complex reciprocal relationship. The two cells lineages share a common progenitor, and adipocyte endocrine activity may influence bone metabolism. Recent evidence from animal models suggests that bone cells may contribute regulating energy metabolism.

Sun exposure questionnaire predicts circulating 25-hydroxyvitamin D concentrations in Caucasian hospital workers in southern Italy.

INTRODUCTION: Recent sun exposure should correlate with circulating 25-hydroxyvitamin D [25(OH)D] due to ultraviolet B (UVB)-catalyzed cutaneous synthesis of vitamin D. METHODS: A Sun Exposure Score was calculated for healthy adults using a recall questionnaire assessing daily Time in Sun (<5 min, 5-30 min, >30 min) and Skin Exposure (face/hands; face/hands and arms; face/hands and legs; and "bathing suit") for 1 week in each of the winter and summer (n=47 and 23, respectively; n=18 participated in both). Concentrations of 25(OH)D were measured by DiaSorin RIA on end-of-week sera. RESULTS: Mean serum 25(OH)D was higher in summer than winter (58.6+/-16.5 nmol/L vs. 38.8+/-29.0 nmol/L, respectively, P=0.003 unpaired). The calculated Sun Exposure Score correlated strongly with serum 25(OH)D during summer (Spearman's rho=0.59, P=0.003); based on the Pearson coefficient of determination, summer Sun Exposure Score explained 38% of the variability in summer serum 25(OH)D. The Sun Exposure Score did not correlate with 25(OH)D in the winter (rho=0.19, P=0.210). The summer correlation was largely explained by the Time in Sun (rho=0.58, P=0.004) rather than area of Skin Exposed (rho=0.10, P=0.660). Although there was a correlation between winter and summer Sun Exposure Scores (rho=0.63, P=0.005), there was no summer vs. winter correlation in serum 25(OH)D (rho=0.08, P=0.76). CONCLUSION: This simple 1-week sun exposure recall questionnaire predicted summer serum 25(OH)D concentrations, accounting for 38% of the variability in 25(OH)D among healthy Italian adults.

Structural aspects of the solvation shell of lysine and acetylated lysine: A Car-Parrinello and classical molecular dynamics investigation.

Lysine acetylation is a post-translational modification, which modulates the affinity of protein-protein and/or protein-DNA complexes. Its crucial role as a switch in signaling pathways highlights the relevance of charged chemical groups in determining the interactions between water and biomolecules. A great effort has been recently devoted to assess the reliability of classical molecular dynamics simulations in describing the solvation properties of charged moieties. In the spirit of these investigations, we performed classical and Car-Parrinello molecular dynamics simulations on lysine and acetylated-lysine in aqueous solution. A comparative analysis between the two computational schemes is presented with a focus on the first solvation shell of the charged groups. An accurate structural analysis unveils subtle, yet statistically significant, differences which are discussed in connection to the significant electronic density charge transfer occurring between the solute and the surrounding water molecules.

Skeletal turnover, bone mineral density, and fractures in male chronic abusers of alcohol.

BACKGROUND: Chronic alcohol abuse is a risk factor for osteoporosis and fractures, whose pathogenesis is still unclear. We investigated the influence of alcoholism and other risk factors on calcium and skeletal metabolism, bone mineral density (BMD), and fractures. MATERIALS AND METHODS: In 51 chronic male alcoholics without liver failure and 31 healthy controls, serum total and ionised calcium, phosphate, creatinine, 25-hydroxy vitamin D (25OHD), PTH, total (ALP) and bone-specific (BALP) alkaline phosphatase, osteocalcin (BGP), carboxy-terminal telopeptide of type I collagen (beta-CTx), osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) were assessed. In patients only, we also measured serum testosterone, 17-beta estradiol, LH, and IGF-I. BMD was measured by dual energy x-ray absorptiometry at lumbar spine (LS-) and femur [neck (FN-) and total hip (TF-)]. Vertebral fractures were identified by a semiquantitative method on thoraco-lumbar spine x-ray, non-vertebral fractures (as life-style factors) by history. RESULTS: Alcoholics were leaner, had significantly higher ALP and BALP, and lower BGP and 25OHD levels than controls. No significant difference in other calcium and bone metabolism parameters was found. OPG/RANKL ratio was significantly higher in alcoholics. Beta-CTx negatively correlated with abuse duration. OPG positively correlated with daily alcohol assumption and with indexes of liver cytolysis. Though LS-, FN- and TF-BMD of alcoholics and controls did not significantly differ, patients had a much higher prevalence of vertebral fractures. The same was found considering both vertebral and non-vertebral fractures. CONCLUSIONS: Ethanol-induced skeletal damage seems mainly dependent on negative effects on bone formation. Lifestyle factors and traumas likely contribute to the high fracture incidence of alcohol abusers, independently of BMD.

Skeletal involvement in adult patients with endogenous hypercortisolism.

Overt endogenous glucocorticoid excess is a well-recognized cause of bone loss and osteoporotic fractures. Cortisol excess inhibits bone formation, increases bone resorption, impairs calcium absorption from the gut, and affects the secretion of several hormones (in particular gonadotropins and GH), cytokines, and growth factors, influencing bone metabolism. The glucocorticoid excess mainly affects trabecular bone, leading to vertebral fractures in up to 70% of patients. Osteoporotic fractures may be the presenting symptom of an otherwise silent glucocorticoid excess and can precede the diagnosis of hypercortisolism by up to 2 yr. The removal of glucocorticoid excess leads to a recovery of bone mass which is, however, often incomplete and delayed, although it reduces the risk of osteoporotic fractures. Bisphosphonate therapy has been suggested to be useful in maintaining bone mass in these patients. Subclinical hypercortisolism, a condition of impaired hypothalamic- adrenal-axis homeostasis without the classical signs and symptoms of glucocorticoid excess, is a recently defined entity, which has been shown to be associated to increased bone resorption, bone loss, and high prevalence of vertebral fractures regardless of gonadal status. However, data about the effect of this subtle glucocorticoid excess on bone are still scarce and conflicting. Moreover, it is not yet known whether removing the cause of subclinical hypercortisolism leads to a recovery of bone mass and reduces the risk of osteoporotic fractures. Finally, recent data suggest that subclinical hypercortisolism is a common and underrated finding in patients with established osteoporosis. In summary, it is crucial to evaluate the risk of osteoporosis and fractures in patients with glucocorticoid excess; on the other hand, it also seems advisable to screen for glucocorticoid excess patients with osteoporotic fractures without known secondary causes of osteoporosis.

Role of thoracic ultrasound in the assessment of pleural and pulmonary diseases.

Although numerous studies have been conducted on the use of ultrasonography (US) for the examination of thoracic structures, this procedure is not as widely accepted as abdominal US. The newer portable scanners can be used at the bedside to detect pleural malignancies and effusions, as well as peripheral lung nodules of the lung, even in seriously ill patients. Focal thickening of the pleura can be easily detected with US and further investigated with a US-guided biopsy. US guidance can also be used during percutaneous drainage of pleural effusion or transthoracic biopsy of peripheral lung lesions, thus reducing the incidence of procedure-related pneumothorax to almost zero. We review the current literature on thoracic US and present our clinical experience with the technique in large groups of patients with pleural and peripheral lung diseases.

Large-scale motions and electrostatic properties of furin and HIV-1 protease.

We present a comparative study between two members of serine and aspartic proteases complexed with a peptide substrate. The same computational setup is used to characterize the structural, electrostatic, and electronic properties for the Michaelis complex of furin, a serine protease, and of the aspartic protease from HIV-1. In both cases plane-wave density functional theory (PW-DFT) and empirical force-field-based molecular dynamics calculations are used. For furin, calculations are extended to the complex with the intermediate of the first step of the reaction. Comparisons are also made with results from recent PW-DFT investigations on both families of enzymes and with the same chemical groups in an aqueous environment. It is found that the substrate carbonyl group is more polarized in the furin complex than in the HIV-1 protease one. A further difference regards the large-scale motions of the complexes as a whole and local conformational fluctuations at the active site. The global and local fluctuations are well coupled for HIV-1 protease but not for furin. Thus, despite some chemical analogies in the first step of the reaction mechanism, furin and HIV-1 protease complexes appear to be characterized by a different interplay of electrostatics and conformational fluctuations.

[Primary hyperparathyroidism]. / Iperparatiroidismo primitivo.

Primary hyperparathyroidism (PHPT) is characterized by excessive PTH secretion in respect to calcium homeostasis needs, due to parathyroid adenoma (80% of cases), hyperplasia (15-20%), or carcinoma (1-2%). In familial forms of PHPT, several mutations have an established role: menin gene for MEN type 1, RET for MEN type 2a, calcium-sensing receptor gene for familial hypocalciuric hypercalcemia, parafibromin gene for PHPT-jaw tumour and carcinoma. Etiology of sporadic adenomas (80% of PHPT cases) is less defined, being most commonly found a mutation of menin gene or activation of PRAD1 oncogene. In recent years, the classical features of the disease became less common. Typically, bone involvement is now represented by a reduced bone mass at skeletal sites more rich in cortical tissue. Prominently trabecular skeletal sites are relatively spared, because of the anabolic effects of a slight PTH excess on trabecular tissue. PHPT patients may have increased fracture risk, though it is not clear why bone damage is more severe in a subgroup of patients. Clinical features of hypercalcemia may be fatigue, anorexia, thirst, and polyuria. Vague neurological and psychiatric symptoms, such as weakness, anxiety, depression, paresthesias, and muscular cramps may ameliorate after parathyroidectomy. Recent reports indicate increased cardiovascular mortality in PHPT patients. Diagnosis is based on the detection of hypercalcemia, together with inappropriately high serum PTH levels. Preoperative localization of the diseased glands is mandatory in persistent or recurrent PHPT, as like as when minimally invasive surgery is planned. High resolution ultrasonography and SPECT double-phase 99m Tc-sestamibi scintigraphy are the most commonly employed techniques. Intraoperatory PTH assay may confirm successful surgery when serum concentrations decrease more than 50%. Surgical therapy is indicated in patients with renal or skeletal complications, such as in those with previous parathyrotoxic crisis. Many surgeons in recent years adopted minimally invasive parathyroidectomy. Medical treatment is an option for patients unwilling or unfitted for surgery because of severe concomitant diseases. Employed therapy includes estrogens, SERMs, bisphosphonates and calcimimetics.

Prevalence of hypercalcemia in hospitalised patients: effects of "correction" for serum albumin values.

Hypercalcemia is ideally detected by the measurement of serum ionised calcium. Because this is not widely available, in common clinical practice "albumin-corrected" calcium values are often utilized. Our study investigated whether the method used to measure serum albumin concentration may significantly interfere in the derived serum calcium values and, consequently, in the identification of hypercalcemic patients. In 170 consecutive patients admitted to our Department of Internal Medicine we measured serum total calcium, total protein, and albumin by colorimetric method; albumin concentration was also derived by electrophoresis assessment. After correcting serum calcium for colorimetrically (CA) and electrophoretically (EA) measured albumin values, the detected frequencies of hypercalcemia were compared, utilizing different cut-off limits (i.e. 11.0, 10.4 and 10.2 mg/dl). In our patients, the CA values were significantly lower than EA levels. As a consequence, EA-corrected calcium, as well as total calcium concentration were significantly lower than CA-corrected values. This may also account for the very different prevalence of hypercalcemic patients identified by serum total, EA-corrected and CA-corrected calcium values. Our data therefore indicate the importance of the method of albumin measurement in the determination of "corrected" calcium concentration.

Dehydroepiandrosterone sulfate and bone resorption rates as reflected by serum levels of C-terminal telopeptide of type I collagen: a study in healthy men.

Sex steroid hormones contribute to the physiological regulation of bone turnover in males. To address this issue, we investigated serum estradiol (E2), total testosterone (T), and DHEAS concentrations, along with serum levels of carboxy-terminal telopeptide of type I collagen (sCTx), in a sample of 76 healthy men aged 23 to 87. The concentration of sCTx declined with age. Both T and DHEAS, at variance with E2, showed a significant age-related decline. T, DHEAS and sCTx significantly (p<0.01) correlated with each other. DHEAS and T were significantly associated after correcting for age (r=0.35, p=0.002) or body mass index (r=0.65, p<0.0001). DHEAS, but not T, significantly correlated with sCTx after correcting for age (r=0.26, p=0.026, and r=0.20, p=0.08, respectively). Stepwise multiple regression analysis showed that only DHEAS (but not T or E2) was a significant independent predictor of sCTx (p=0.0001). Our results show that adrenal androgens play a crucial role in regulating bone resorption in aging men.